(1) Look at the color: The higher the purity of gold jewelry, the darker the color. In the absence of a gold medal, the general fineness can be determined according to the following colors (based on cyan gold). The so-called green gold is just silver in gold); The fineness of deep red yellow is above 95%, light red yellow is 90-95%, light yellow is 80-85%, blue yellow is 65-70%, blue white is only 50-60%, and yellow white is less than 50%. The so-called seven greens, eight yellows and nine reds can be used for reference. (2) Balance weight: The specific gravity of gold is 19.32, which is heavier than silver, copper, lead, zinc, aluminum and other metals. Because the volume of gold is more than 40% heavier than that of silver, 1.2 times heavier than that of copper and 6. 1 times heavier than that of aluminum. Gold jewelry should feel heavy in your hand, while fake gold jewelry feels light and floating. This method is not suitable for gold ornaments with precious stones.
(3) Look at hardness: Pure gold is soft and low in hardness, and shallow marks can be drawn with nails, and tooth marks can be left after biting. Gold ornaments with high color are softer than those with low color, and the more copper they contain, the harder they are. Bending method can also be used to test hardness. Pure gold is soft and easy to bend, and the lower the purity, the more difficult it is to bend.
(4) Listen to the sound: When real gold with a purity of over 99% is thrown on the hard ground, it will beep, without rhythm and elasticity. Fake or low-quality gold sounds crisp and dull, generally making a "Dangdang" sound, with a lingering sound, and violently beating after landing.
(5) Burning with fire: Burn the jewelry to be identified with fire (do not melt and deform the jewelry), and observe the color change after cooling. If the surface is still golden, it is pure gold; If the color darkens or turns black to varying degrees, it is not pure gold. Generally, the lower the fineness, the thicker the color, and all of them turn black, indicating that they are fake gold ornaments.
(6) Look at the mark: domestic gold ornaments are purified and prepared according to international standards, and marked with marks, such as "24K" for "full red" or "pure gold"; 18K gold, marked with the words "18K". If the color is lower than Locke, the K-gold seal number cannot be printed according to regulations. Nowadays, criminals in the society often make fake brands and imitate stamps, and use rare gold, inferior gold and even brass as real gold. Therefore, the identification of gold ornaments should be based on the comprehensive judgment of samples to determine the authenticity and color.
Platinum and platinum
In fact, simply speaking, platinum is an element and platinum is a mixture. Platinum: Platinum is chemically more stable than gold and its price is higher than that of Huang Jingui. Used to make high-end jewelry. The "pt900" or "pt950" seen on jewelry products represent that the platinum content in jewelry is 90% and 95% respectively. The purity of pure platinum jewelry is generally 95%, while the purity of 18k gold is only 75%. No metal can be completely pure, and there are impurities mixed with other metals. Platinum has almost no impurities, and its purity is extremely high. It will not fade and change color, and it can still maintain its luster over time. The pure white luster of platinum can well reflect the true light of diamonds. Rare platinum is 35 times as rare as gold. In the world, it can only be mined in a few places, mainly South Africa and Russia, as well as a few areas in Zimbabwe, Canada and South America. Only 88 tons of platinum is made into ornaments every year, while 2700 tons of gold. The quantity of platinum ore is less, and the ratio of platinum ore to gold ore is 1 to 10. The density and weight of Eternal Platinum make it more durable than other jewelry metals. All precious metals leave scratches, including platinum. However, the scratches on platinum only move the metal and will not reduce its volume, while the scratches on gold will bring wear and reduce the volume of gold. If visible scratches appear on platinum, qualified jewelers can polish it again. Platinum: A mixture containing gold (au) and a small amount of other metals. The highest purity of platinum visible in the market is 75%. It is made of 75% gold and 25% silver, nickel, copper and other metals, that is, white gold. Marked as 18k platinum, 750 platinum, 750g, etc. How to distinguish platinum from platinum depends mainly on the imprint on jewelry, in which the ring will be marked on the inner ring and the necklace will be marked on the buckle. Platinum jewelry containing more than 990‰ platinum is generally marked with "sufficient platinum". The symbol "p950" indicates platinum with a purity of 950‰. Platinum should be marked kk number. K refers to the gold content. For example, those marked with 18k white, 750g, 750k gold and au750 are all platinum with a gold content of 18k. The purity of platinum jewelry is not expressed by "K". White gold and platinum jewelry sold in the market are not platinum jewelry. When purchasing platinum jewelry, the operator should be required to issue an invoice, and the invoice should indicate whether it is platinum or white 18k gold. It is best to indicate the weight of the jewelry, so it is easier to claim compensation in case of fraud.